mta083.gca.to has no CNAME records.
Question and response
Question
dig mta083.gca.to. NS
Answer
The response has no answer records.
Authority
gca.to. 424 SOA ns-mail02.getcourse.ru. hostmaster.gca.to. 972945 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0